import { CodeTabs, CodeTab } from "docs-ui"

export const metadata = {
  title: `Cart Module`,
}

# {metadata.title}

The Cart Module provides cart-related features in your Medusa and Node.js applications.

## How to Use Cart Module's Service

You can use the Cart Module's main service by resolving from the Medusa container the resource `Modules.CART` imported from `@medusajs/framework/utils`.

For example:

<CodeTabs groupId="resource-type">
  <CodeTab label="Workflow Step" value="workflow-step">

```ts title="src/workflows/hello-world/step1.ts"
import { createStep } from "@medusajs/framework/workflows-sdk"
import { Modules } from "@medusajs/framework/utils"

const step1 = createStep("step-1", async (_, { container }) => {
  const cartModuleService = container.resolve(
    Modules.CART
  )

  const carts = await cartModuleService.listCarts()
})
```

  </CodeTab>
  <CodeTab label="API Route" value="api-route">

```ts title="src/api/store/custom/route.ts"
import { MedusaRequest, MedusaResponse } from "@medusajs/framework/http"
import { Modules } from "@medusajs/framework/utils"

export async function GET(
  req: MedusaRequest,
  res: MedusaResponse
): Promise<void> {
  const cartModuleService = req.scope.resolve(
    Modules.CART
  )

  res.json({
    carts: await cartModuleService.listCarts(),
  })
}
```

  </CodeTab>
  <CodeTab label="Subscriber" value="subscribers">

```ts title="src/subscribers/custom-handler.ts"
import { SubscriberArgs } from "@medusajs/framework"
import { Modules } from "@medusajs/framework/utils"

export default async function subscriberHandler({ container }: SubscriberArgs) {
  const cartModuleService = container.resolve(
    Modules.CART
  )

  const carts = await cartModuleService.listCarts()
}
```

  </CodeTab>
</CodeTabs>

---

## Features

### Cart Management

Store and manage carts, including their addresses, line items, shipping methods, and more.

```ts
const cart = await cartModuleService.createCarts({
  currency_code: "usd",
  shipping_address: {
    address_1: "1512 Barataria Blvd",
    country_code: "us",
  },
  items: [
    {
      title: "Shirt",
      unit_price: 1000,
      quantity: 1,
    },
  ],
})
```

### Apply Promotions

Apply promotions or discounts to line items and shipping methods by adding adjustment lines that are factored into their subtotals.

```ts
const lineAdjustments = await cartModuleService.addLineItemAdjustments({
  item_id: "cali_123",
  code: "50OFF",
  amount: 500,
})

const shippingAdjustments =
  await cartModuleService.addShippingMethodAdjustments({
    shipping_method_id: "casm_123",
    code: "FREESHIPPING",
    amount: 1000,
  })
```

### Cart Context and Scoping

A cart is scoped to a sales channel, region, and a customer.

The Medusa application links the Cart Module to each of their respective modules, providing features like:

- Checking product availability in a sales channel.
- Retrieving pricing per region.
- Applying promotions based on the customer's group.